Vastus Medialis

Musculus vastus medialis

Lower Body LegsQuadricepsAnterior Compartment of the ThighAnterior Chain

The teardrop-shaped muscle on the inner thigh just above the knee, the vastus medialis extends the knee and its oblique (VMO) fibers medially stabilize the patella, opposing the lateral pull of the vastus lateralis. It is heavily emphasized in the final ~15 degrees of knee extension (terminal knee extension), making it a focus in knee-rehab and patellofemoral programs. Deep squats and full-range leg extensions develop it best.

Actions

Knee extension, Patellar stabilization

Origin

Lower part of the intertrochanteric line, spiral line, medial lip of the linea aspera, medial intermuscular septum, and tendon of adductor magnus.

Insertion

Medial border of the patella and quadriceps tendon, continuing to the tibial tuberosity via the patellar ligament.

Innervation

Femoral nerve (posterior division, L3–L4).

Blood supply

Femoral artery and descending genicular artery; lateral circumflex femoral artery.

Wikipedia ↗

quadslegsknee-extensionpatellar-trackingteardropvmo